This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of the study and substudy is: 1- To see how well different combinations of anti-HIV drugs work to decrease the amount of HIV in the blood (viral load) of people who have never received anti-HIV therapy. 2- To evaluate the safety and tolerability of the three anti-HIV treatments used in this study. 3- To learn about the metabolic changes in participants receiving one of the three anti-HIV treatments given in A5257 as their first antiretroviral regimen. The metabolic changes we will be measuring are in body fat, bone, the blood vessels, blood sugar, cholesterol, and kidney function. Eligible subjects will be randomized to receive one of the three anti-HIV treatments: 1) Atazanavir (ATV) and ritonavir (RTV) with tenofovir (TDF) and emtricitabine (FTC) 2) Raltegravir (RAL) with tenofovir (TDF) and emtricitabine(FTC) 3) Darunavir (DRV) with ritonavir (RTV) with tenofovir (TDF) and emtricitabine (FTC) The current treatment guidelines recommend that treatment-na[unreadable][unreadable]ve, HIV-infected patients be treated with a triple drug regimen that includes two Nucleoside reverse transcriptase inhibitors (NRTIs) and either efavirenz (EFV) or one of three boosted Protease inhibitors (PIs). However, there are patients for whom treatment with an EFV-containing regimen is undesirable due to side effects, teratogenicity, pharmacokinetic (PK) interactions, or acquired NNRTI-resistant virus. Alternative regimens are needed for these populations, and a more thorough understanding of the differences between possible NNRTI-sparing regimens is missing from the literature.